What this reversing starter is and where it fits
The Siemens 3RK1301-1BB00-1AA2 is a SIMATIC-branded reversing motor starter designed for direct-on-line reversing of three-phase motors up to CLASS 10 trip protection. It integrates the reversing contactor, overload relay, and communication interface into a single 265 mm high, 90 mm wide, 120 mm deep package that plugs onto a terminal module — no wiring between the power and control sections. The 24 V DC control supply (20.4 to 28.8 V operating range) powers the onboard PROFINET and PROFIBUS DP interfaces, so the starter reports directly to a PLC without a separate gateway.
Key ratings and what they mean for fit
CLASS 10 trip class means the overload relay will trip within 10 seconds at 7.2× the thermal setting — standard for protecting standard induction motors during a stall or locked-rotor condition. The 50 kA rated short-circuit current at 400 V tells you this starter can be installed on a supply with fault current up to that level without needing an upstream current-limiting fuse; it's sized for industrial distribution panels with high available fault current. Pollution degree 3 at 400 V means the starter is rated for conductive pollution environments — typical of control panels in machine shops, foundries, or food processing areas where dust and moisture are present. The operating temperature range of 0 to 60 °C covers most indoor industrial applications but not freezer or outdoor enclosures without derating.
Panel integration notes
Mounts vertically or horizontally on a DIN rail via the pluggable terminal module. The 90 mm width occupies three standard 22.5 mm module spaces — plan your rail layout accordingly. The 265 mm height is taller than a typical contactor; verify enclosure depth clearance for the 120 mm depth plus wiring space. Screw-type terminals on the main power infeed accept standard ring or fork lugs. Vibration resistance is 2g continuous and shock resistance is 5g / 11 ms, so it holds up in machine-mounted panels on presses or conveyors.